li {
   list-style: square ;
  /*  list-style-type: square;*/
  visibility: hidden;
}

table{
    border-collapse: collapse;
}



th, td {
    border: 1px solid black;

    
}

#app
{

    width: 100px;
    height: 100px;

    border: 1px solid #bb0000;

    color: #bb0000;
    background-color: #0051d8;

    background-image: url("./img.webp");
    /* 设置背景图片的大小 百分比、contain、cover */
    background-size: cover;
    /* 设置背景图片的重复 */
    background-repeat: no-repeat;
    /* 水平方向：left center right */
    /* 垂直方向：top center bottom */
    background-position: center;


}

#xiehaoapp
{
width: 1000px;
height: 1000px;
border: 1px solid #bb0000;

color:#bb0000;
background-color: #0051d8;

background-image: url("./img.webp");

background-size: 100%;

background-position: 40px;
background-repeat: no-repeat;
    



}





/*


background-color 背景颜色
- background-image 背景图片
- background-size 背景尺寸
- background-repeat 背景重复
- background-position 背景位置

- background 背景

> background: url('...xxx') cover no-repeat;
*/


/*

#d1 {
    width: 400px;
    height: 400px;

    background-color: #abc;

    float: right;
}

#d2 {
    width: 500px;
    height: 500px;

    background-color: #aaa;

    float: right;
}

#d3 {
    clear: both;
    height: 200px;
    background-color: #f00;
}


*/

#d1{
    width:400px;
    height: 400px;

background-color: #aaa;
float:left;



}

#d2{
    width:500px;
    height:500px;
    background-color:#aaa;
    float:left;

}

#d3{
height:200px;
background-color: #f00;



}

.ddddd {
    width: 400px;
    height: 400px;

    background-color: #00ff00;
}
